Is Sharon Osbourne leaving 'America's Got Talent'?

Updated at 5:34 p.m. PT: An NBC source told TODAY.com that the network was surprised by Sharon Osbourne's Tuesday morning tweet that she was leaving "America's Got Talent." The revelation came out of the blue on a day when the show was taping with the longtime judge, and no one at the network seemed to know she was considering leaving the position.

Paul Telegdy, president of alternative programming, told us that she's on board for at least the rest of the season.

"We're in the middle of the season and nothing has changed. It was just two friends chatting on Twitter, it didn't mean anything," Telegdy told TODAY.com at the Television Critics Association's summer press tour in Beverly Hills.

Original story: Let the judging search begin. Sharon Osbourne — the longest tenured judge on "America's Got Talent" — has said she won’t return for next season.

Sharon shocked fans this morning by breaking the news via Twitter: “My darling @HowardStern, money is not the reason I’m not returning to @nbcagt, it’s because…”